With the 2 Argosy Spacecraft safely on their transfer trajectory to Mars, they close together, rendezvousing in a nose to nose orientation. EVA teams from both ships rig 100 foot tethers between the ships, installed on computer-controlled tensioners. As the ships slip past the Moon, the crews finish up and return to their respective vehicles. Once secured, the appropriate attitude jets will fire to spin the 2 craft around their center of mass to provide centrifugal force equal to about 1/3 of an Earth gravity ( Mars gravity) in the crew modules. The craft will be despun and separated for the deceleration into Mars orbit.For details about the 1969 proposal I'm basing this series on, here is a very good synopsis: [link]

Exceptional modeling and composition – I really must commend your attention to detail in your historical research. I have seen David Portree’s Beyond Apollo Blog post on the 1968 Boeing/North American Rockwell Mars mission proposal – but I had not seen Von Braun’s tweaked mission plan before. Thanks for the link! … In just a few views you have given me a new perspective, and I’ve become a major fan of your work.

It's pretty neat - but I'm definitely more a fan of the Mars-Direct approach.

Actually, what I'd love to submit is... Err.... A somewhat complex design. But it involves VASIMR engines (39-day transit), and every vehicle being reusable except for the surface habs. So that means reusable Mars-SSTO's, and a reusable Trans-martian VASIMR "bus".

And I really mean submit it. I'm destined for the Aerospace industry. And I'm looking forward to having talking opportunities with some engineers as a NASA intern. I've got lots of questions and ideas.And an ever-present fear of them being stolen

The main Hydrogen tank, and the shroud, are 33 feet in diameter, with the Mission Module being 22 feet in diameter.I'm glad you're looking for a career in astronautics--we desperately need some new perspectives in NASA and private industry.

Thanks. I keep hearing it's a good field to go into, even though they just stopped the shuttle program. Seems a bit confusing to me, but then again, there's always something to replace it - Constellation, then SLS.

Private industry is where I want to go, and I guess that's where the field is expanding?

Private industry, go the farthest the cheapest and the safest. I've got some new perspectives, but I hope they're good ones

Hmm... Speaking of which...I can imagine a lot of cost savings coming from building things heavier. I think engineers fear mass too much... If the SSME's were to operate not so near structural limits, they'd be heavier, sure, but enormous amounts could be saved on re-usability and refurbrishment... Of course mass does need to be saved, especially on propellant tanks, but the bottom line is cost, not mass, and LOX/RP-1 is a lot cheaper than an engine or a system that needs major overhaul every flight Right?

Why tether two separate crew module together? Wouldn't it make more sense to have all the crew in one location and use something else as a counterweight. The propulsion module, or anything carrying cargo you won't use in transit would work.

I've actually been going back over the research materials to see if I can find an answer to your really good question--and I've come up empty! The whole rotational gee concept was apparently a late add-on to the mission profile, in response to new information trickling out of Russia on long-term biological effects of weightlessness, and our own Skylab results. It does seem like a better idea to spin the 2 ships separately, to maintain the redundancy position of , if one has trouble, the other most likely won't have the same trouble.

Well, like most NASA efforts these days, this one was perpetually being replanned, since design studies are a way to keep engineers employed, with no actual need to bend metal. I should point out that each ship was capable of supporting the other ship's crew in an emergency. (which would mean aborting the mission, and taking the fastest route back to Earth.)